3 Answers
3

There are alternatives to patenting.
If you are for example intending to use most of the original product, then consider using a registered design, this varies from country to country, but is way cheaper and quicker. The registered design is for the "look and feel" of the product (patents are more about function).
Then you advertise it, sell a handful, once it generates a bit of interest, go back to to original manufacturer and parley with them. They can make your improved design , and sell to you at OEM prices, you get to pocket the markup to retail typically half the sticker price.
So two options

(a) Patent your new approach, setup manufacturing activity, work
years of 18hr days, fight off the original inventor, spend $100k,
have a turnover of $110k in 5 years time, net profit = 10k.

(b) Do some mods to existing device, register design ($100/year), pay
original inventor $50k/year to make product you can sell in one years
time for $100k/year, year after that sell the registered design to
original inventor for $20k , walk away after 2 years with $120k in
your pocket.

The patent gives one the "right to manufacture" , a registered design gives you the "right to sell" (assuming customers want to buy your faddish variant).

Thx for the info. Although, I should have mentioned that my new product is a formula that has been modified from someone elses existing patented formula. My new formula will be in a totally new field.
– 101heartbeatDec 29 '14 at 2:03

Is that a chemical formula (recipe) or a mathematical formula.
– BobTDec 30 '14 at 8:34

If you are using an existing recipe but changing the end-use , that's not particularly novel, however incorporating an existing recipe (product) as part of a novel method or process is potentially patentable. If you start with the patented recipe, conduct documented experiments with it and find the optimal ingedient ranges to suit your method , you will have a stronger case.
– BobTDec 30 '14 at 8:42

Yes Bob It's a an existing chemical formula that I added ingredients to in-order to create a {new product(gel)}in a totally different field.. Thx again
– 101heartbeatDec 31 '14 at 3:13

hi need to use current patented product as part of new patent ingredianr
– user13411Feb 4 '15 at 6:17

Patents are there to give the "inventor" an exclusive right to manufacture "products" for a certain period.
So if you "buy" an item of a product, you can do what you like with it, the original inventor has already got his money. So it's generally fairly pointless for example buying bicycles, cutting and re-welding the frames to make tandem bicycles, unless you can make an additional profit from tandem cycles , then it's good luck to you.
If you want to file a patent, then this has to be for the design of your "novel" product, but to actually benefit from a patent you need to be able to manufacture your product, however the costs of manufacture and patenting your "new" product may be less economic than actually modifying them. (Speaking from experience, having imported a container load of items then swapping a small PCB for one of my own)
So in your patent you need to refer to the bicycle patent as prior art. If your design is sufficiently "novel" then the patent will be granted , eventually, but most often will be rejected as just an obvious extension of prior art.
Note that if you do get a patent granted for your "tandem" , if you then sell it , minus all the tandem parts, you will be infringing the "bicycle" patent.

The intent of the patent process is to encourage improvements to existing ways of doing things.

It is also important to carefully read the "claims" in the patent you are improving upon, sometimes it seems from the description that the applicant has described all sorts of features, but only claimed one subtle feature. For example the patent of the bicycle might talk about all things, but the only claims are "having two springs in the seat" , so just make your tandem claim have "two seats with suspension means" and have secondary claims mentioning suspension means of foam monoblocks, and another with a "plurality of springs" , so the worst the original bike inventor can do is make one of your subclaims restricted to one spring or 3 or more.
Hope this helps.

A patent gives the patentee the right to make, sell, use, or import into the USA the patented product. You cannot USE the patented product as a starting material for the synthesis of your own product because you would be infringing the patent. You may be able to purchase a license from the patentee to buy and use the patented product to make and sell a modified version.

Minor correction on an otherwise good post--a patent doesn't give you the right to do any of those things, it gives you the right to stop others from doing it: what's called a "negative right." The distinction here comes into play in cases like that of this question, where you could patent some aspect of an improvement to something that's already patented, but that wouldn't give you the right to produce it without consent from the original patent holder.
– Matthew Haugen♦Aug 3 '15 at 17:22

The key is whether the end-product you are selling infringes on a patent. Depending on the context of the question, there might be other ways of working around licensing the patent. Consider a case where you are creating and selling a separate component (or set of components) that can be attached to the patented product in question. And in agreement with @MatthewHaugen, you can absolutely patent non-obvious improvements or novel uses of existing patents. See also this related question.
– vallismortisAug 3 '15 at 20:02